The invention concerns a supply air terminal device.
Control of the induction ratio has become a requirement in supply air terminal devices, wherein fresh air is supplied by way of the supply air terminal device and wherein room air is circulated using the device. This means that the ratio between the flow of circulated air and the flow of fresh air can be controlled.
In the present application, primary airflow means that flow of supply air, and preferably the flow of fresh supply air, which is supplied into the room or such by way of nozzles in the supply air manifold. Secondary air flow means the circulated air flow, that is, that air flow, which is circulated through a heat exchanger from the room space and which air flow is induced by the primary air flow.
For implementation of the above-mentioned control the present application proposes use of a separate induction ratio control device. According to the invention, the induction ratio control device may be located below the heat exchanger in the mixing chamber. Control may hereby take place by controlling the flow of circulated air L2. The more the air flow L2 is throttled, the lower the induction ratio will be, that is, the air volume made to flow through the heat exchanger becomes smaller in relation to the primary air flow.
Besides the above-mentioned way of controlling the induction ratio, such a control device may also be used, which is formed by a set of nozzles formed by nozzles in two separate rows opening from the supply chamber for fresh air, whereby the nozzles in the first row are formed with a bigger cross-sectional flow area than the nozzles in the second row. The induction ratio control device includes an internal aperture plate used for controlling the flow between the nozzle rows of the said nozzles.